The present invention relates to a data copy technique for data held in a computer system. The present invention relates particularly to a copy control method for adjusting a designated, data copy acquisition time and for calculating an optimal acquisition time, and a storage device therefor.
Conventionally, a variety of methods have been developed that provide for the backing up of data, held in a computer system, at a designated time during which the job performance loads are not concentrated.
For example, as a method for the copying of data at a selected time, a method and an apparatus for backing up a database at a designated time are disclosed in JP-A-2006-155676. According to this method and apparatus, a batch process is performed without halting the updating of a database that is currently being employed by an online system.
Further, as another backup example, a CDP (Continuous Data Protection) technique is disclosed in U.S. Pat. No. 7,111,136. According to this technique, data written in primary storage are tracked and capture processes are performed constantly, not just at designated times, and changed portions are written in secondary storage as members of a timed series. Thus, beginning at a specific time in the past, data written at arbitrary times can be reproduced.